Autostereographic print element

ABSTRACT

Autostereographic prints are made by photographic means in which a transparent support having one surface lenticulated carries on the opposite surface at least one radiation-sensitive layer such as a silver halide emulsion layer over which the sensitive layer farthest from the support is coated a highly reflective layer such as one containing titanium dioxide pigment, which is preferably permeable to the processing baths required to process the radiation-sensitive layer.

United States Patent 1 Howe et al.

3,751,258 1 Aug. 7, 1973 I 1 AUTOSTEREOGRAPHIC PRINT ELEMENT [75]Inventors: Donald J. Howe; John C. Hoppe,

both of Spencerport, NY.

[73] Assignee: Eastman Kodak Company,

Rochester, N.Y.

[22] Filed: Oct. 29, 1970 [21] Appl. No.: 85,214

[52] US. Cl. 96/81, 96/40 [581 Field of Search 96/40, 81, 85; 350/167[56] References Cited 2 UNITED STATES'PATENTS 3,649,283 3/1972Christensen et al7 96/85 2,726,154 12/1955 Land 96/81 3,595,652 7/1971Farney 96/76 1,918,705 7/1933 lves 96/81 2,140,702 12/1938 Kanolt 96/402,500,51 l 3/1950 Bonnet 96/40 Primary Examiner-Norman G. TorchinAssistant Examiner-Edward C. Kimlin Att0rneyW. H. J. Kline, B. D. Wieseand H. E. Byers [57] ABSTRACT Autostereographic prints are made byphotographic means in which a transparent support having one surfacelenticulated carries on the opposite surface at least oneradiation-sensitive layer such as a silver halide emulsion layer overwhich the sensitive layer farthest from the support is coated a highlyreflective layer such as one containing titanium dioxide pigment,whichis preferably penneable to the processing baths required to processthe radiation-sensitive layer.

10 Claims, 1 Drawing Figure PATENTED 7973 I 3.751.258

/2 LEN T/CULES SUPPORT \x p (RAD/A r/0/v SENSITIVE LAYER /-R\ F-'--REFLECTIVE LAYER DONALD J. HOWE JOHN c HOPPE INVENTORS ATTORNEYAUTOSTEREOGRAPIIIC PRINT ELEMENT BACKGROUND OF THE INVENTION Thisinvention concerns autosterographic photographic prints, in particular aradiation-sensitive element comprising a lenticulated surface to produceprints which appear to be in three dimensions.

It has been proposed to make autosterographic prints by photographicmeans of parallax sterograms, parallax panoramagrams, and the like. Forexample, reference is made to Kingslake, Applied Optics and OpticalEngineering," Volume II, pp. 108-1 16, Academic Press, New York, 1965.

Previous workers in the field have proposed the use of a transparentlenticular screen in combination with a photographic element to achievethe desired autostereogram. Autostereograms for viewing by reflectedlight were proposed in which the reflecting material is applied afterprocessing to the surface of the photographic image opposite thelenticulated surface by a variety of techniques; for example, see U.S.Pats. Nos. l,9l8,705 and 2,500,511 and British Pat. No. 492,186.

When reflection prints are made by ordinary photographic processes,however, the pro belm remains that the reflective layer beneath thephotosensitive layer must be applied or laminated or otherwise put inplace after the photographic processing steps are complete since thereflective layers used are impermeakle to the processing baths. If thealternative approach is used of attaching or affixing in rigidrelationship to the picture element, the lenticular-bearing element,after the processing has been completed, then a severe alignment problemis encountered in assuring the required precise registration of thelenticules with the picture elements. In addition, any dimensionalchanges in the picture element or the lenticulated element relative toeach other, occurring between exposure of the print and finaljuxtaposition of the picture element and the lenticulated element, willdegrade or perhaps destroy the intended stereoscopic effect.

It is an object of this invention .to provide novel autostereographicreflection print elements.

It is another object of this invention to provide an improved processfor preparing autostereographic reflection prints.

It is a further object of this invention to provide an autostereographicreflection print by a process which avoids the problems associated withalignement of lenticules with stereographic information.

A further object is to provide autostereographic prints bp a processwhich results directly in useful prints without need for an additionalstep of applying a reflective layer after photographic processing steps.

Further advantages will be apparent from the description and exampleswhich follow.

SUMMARY OF THE INVENTION In a preferred embodiment, a transparentsupport' comprises cellulose triacetate film support which has beenlenticulated by embossing so that there are 200 lenticules perinch. Onthe other side of the film support is a layer of light snesitive silverhalide emulsion such as a silver chlorobromide elulsion. Over theemulsion layer is a reflective coating comprising gelatin and a titaniumdioxide pigment.

In one process of forming an autostereographic reflection print usingthe element of the invention, a multiple lens camera is employed toexpose a light-sensitive negative element to form a multiplicity ofimages bearing a stereoscopic relationship to one another. Thestereographic images are then exposed on the element of this invention.The exposed element is processed by conventional processing means andthe resulting reflec' t'ion autostereogram viewed directly withoutspecial viewing aids giving a panoramic stereoscopic image over anappreciable viewing angle.

. BRIEF DESCRIPTION OF THE DRAWING The autostereographic reflectionprint element that is the subject of this invention is described withparticular reference to the preferred embodiments thereof. A greatlyenlarged cross section is shown in FIG. 1 of one possibleconfigurationof an integral autostereographic reflection print element.The transparent support layer 11 of suitable material to be describedhereinafter has lenticules l2 embossed or otherwise suitably formed onone surface. On the opposite smooth surface of the support layer iscoated a radiation-sensitive element 13, which can be either aphotographic color or black-andwhite element of one or more layers, andover the radiation-sensitive element is coated a reflective layerDESCRIPTION OF PREFERRED EMBODIMENTS Support materials suitable in thepractice of this invention include those polymeric materials that lendthemselves to. theformation of lenticules by heat embossing, solventsoftening followed by embossing, or a combination of the two; pressureembossing; hotmelt coating followed by embossing as described in U.S.Pat. No. 3,1 10,608 issued Nov. 12, 1963 to Brunson et. al.; and othertechniques for the formation of lenticules. Such polymeric materials ascellulose esters; e.g., cellulose acetate, cellulose triacetate,cellulose butyrate, etc.; polystyrene, etc., may be used.

A polymeric support may be formed by laminating in order to provide asurface which is subject to forming lenticules thereon. For instance, apolyester transparent support could be employed over which a celluloseester or polyolefln layer has been laminated or coated which isparticularly suitable for forming lenticules by a suitakle heat process.It will be appreciated that among the .polymeric materials which can beused are, for example, polyoleflns, particularly the polyolefins fonnedfrom olefins having 2 to 10 carbon atoms, theri copolymers andhomopolymers.

The polymeric surface can be given a treatment to improve the adhesionto the radiation-sensitive material or the like. Typical treatmentswhich are particularly suitable for use with hydrophobic polymers suchas polyoleflns, include treatments with a flame, use of a oxidizingagent such as nitric acid, sodium hypochlorite, chlorine, hydrogenperoxide, sulfuric acid and potassium chromate, etc., electronbombardment, radiation by ultraviolet light, etc.

Electron bombardment of polymeric surfaces is conveniently carried out bmeans of a corona discharge.

Variations in electrical conditions may be used with respect tofrequency, voltage, number of electrodes, spacing between the dischargegap, medium used in the discharge gap, such as an inert gas, ozone, etc.Apparatus disclosed in Rothacker Patents U.S. Pat. Nos. 2,864,755 and2,864,756 can be utilized. The level of electron bombardment or similarsurface treatment of the polymeric surface can be measured by thecontact angle obtained when a drop of distilled water is placed on alevel sample of the polymeric coating. By projecting the image of thedrop and sample on a suitable screen, and measuring the angle of a linetangent to the drop image at the point the drop touches the polymericsample, a contact angle is obtained which can be measured and utilizedto determine the degree of hydrophilicity. Generally untreatedpolyethylene coated paper gives a contact angle of about 90. A contactangle of preferably from about 40 to about 75 improves the adhesion ofhydrophilic coatings and is highly desirable for coatings such ascellulose ester coatings, subbing coatings or the like. Withpolypropylene, the preferred contact angle is preferably less than 54for subsequent coatings.

Typical methods of treating polyethylene by electron bombardment aredisclosed in Traver U.S. Pat. Nob. 3,018,189 directed to methods fortreating the surface of polyethylene with electrostatic discharges tochange the surface properties of the polyethylene with respect toadhesion of materials coated thereon. British Pat. Specification No.715,915 issued to the Visking Corp., published Sept. 22, 1954 alsodiscloses a method and apparatus for treating plastic structures with acorona discharge.

Another method of improving the adhesion to a polymer coated surface isillustrated by Alsup U.S. Pat. No. 3,161,519 issued Dec. 15, 1964 inwhich colloidal silica is employed in a coating over a polyolefinsurface. In the particular disclosure therein, a coating mixturecontaining colloidal silica is coated on untreated polyethylene coatedpaper and dried with hot air at about 150F.

The lenticules can be any shape which will focus an image in the planeof the light snesitive layer, for example, semi-cylindrical,semi-ellipsoidal, parabolic, etc., in cross section. The lenticularfrequency, i.e., number of lenticules per inch, can be from about 50 to500 per inch, and the preferred frequency is from about 100 to 300 perinch. The required support thickness is a function of the curvature ofthe lenticules and the index of refraction of the support material,,asis well known to those skilled in the art.

Radiation-sensitive coatings can include diazo coatings, silver saltcoatings, such as silver halide, silver dye salts, etc.

Radiation-sensitive silver halide emulsions suitable for use with thisinvention can be coarse or fine grain and can be prepared by any of thewell-known procedures; e.g., single-jet emulsions, double-jet emulsions,such as Lippmann emulsions, ammoniacal emulsions, thiocyanate orthioether ripened emulsions such as those described in Nietz et a1 U.S.Pat. No. 2,222,264; lllingsworth U.S. Pat. No. 3,320,069; and McbrideU.S. Pat. No. 3,271,157. Surface image emulsions may be used or internalimage emulsions such as those described in No. Davey et a1. U.S. Pat.No. 2,592,250; Porter et a1. U.S. Pat. No. 3,206,313; Berriman U.S. Pat.No. 3,367,778 and Bacon et al U.S. Pat. No. 3,447,927.

If desired, mixtures of surface and internal image emulsions may be usedas described in Luckey et al U.S. Pat. No. 2,996,382. Negative typeemulsions may be used or direct-positive emulsions such as thosedescribed in Leerrnakers U.S. Pat. No. 2,184,013; Kendall etal. U.S.Pat. No. 2,541,472; Berriman U.S. Pat. No. 3,367,778; SchouwenaarsBritish Pat. No. 723,019; lllingsworth et a1. French Pat. No. 1,520,821;

lves U.S. Pat. No. 2,563,785; Knott et al. U.S. Pat.

2,456,953 and Land U.S. Pat. 2,861,885. Knott et al.

U.S. Pat. No. 2,456,953 and Land U.S. Pat. No.

2,861,885. The emulsions may be regular grain emulsions such as the typedescribe d in Klein and Moisar, J. Phot. Sci., Vol. 12, No. 5,September/October, 1964, pp. 242-251.

Silver halide developing agents used for initiating development of theexposed sensitive element can be conventional types used for developingfilms or papers. Usually, the concentration of developing agent and/ordeveloping'agent precursor employed is about 3 to about 320 mg/ft ofsupport.

Developing agents and/or developing agent precursors can be employedalone or in combination with each other, as well as with auxiliarydeveloping agents. Suitable silver halide developing agents anddeveloping agent precursors which can be employed include, for example,polyhydroxybenzes, alkyl substituted hydroquinones, as exemplified byt-butyl hydroquinone, methyl hydroquinone and 2, 5-dimethylhydroquinone,catechol and pyrogallol; chloro substituted hydroquinones such aschlorohydroquinones such as methoxy hydroquinone or ethoxy hydroquinone;aminophenol developing agents such as 2,4-diaminophenols andmethylaminophenols.

The photographic emulsions employed can also be x-ray or othernon-spectrally sensitized emulsions or they can contain spectralsensitizing dyes such as described in U.S. Pats. Nos. 2,526,632 ofBrooker et a1. lssued Oct. 24, 1950 and 2,503,776 of Sprague issued Apr.11, 1950. Spectral sensitizers which can be used include cyanines,mcrocyanines, styryls and hemicyanines.

The photographic emulsions can contain various photographic addenda,particularly those known to be beneficial in photographic compositions.Various addenda and concentrations to be employed can be determined bythose skilled in the art. Suitable photographic addenda includehardeners, e.g., those set forth in British Pat. No. 974,317; bufferswhich maintain the desired developing activity and/or pH level; coatingaids; plasticizers, speed increasing addenda, such as amines, quaternaryammonium salts, sulfonium salts and alkylene oxide polymers; and variousstabilizing agents, such as sodium sulfite. The photographic silver saltemulsions can be chemically sensitized with compounds of the sulfurgroup such as sulfur, selenium and tellurium sensitizers, noble metalsalts such as gold, or reduction sensitized with reducing agents orcombinations of such materials.

Various photographic silver salts can be used in the practice of theinvention. These include photographic silver halides such as silveriodide, silver bromide, silver chloride, as well as mixed halides suchas silver bromoiodiode, silver chloroiodide, silver chlorobromide andsilver bromochloroiodide. Photographic silver salts which are not silverhalides can also be employed such as silver salts of certain organicacids silverdye salts or 7 complexes, etc.

The photographic silver salts are typically contained in an emulsionlayer comprising any binding materials suitakle for photographicpurposes. These include natural and synthetic binding materialsgenerally employed for this purpose, for example, gelatin, colloidalalbumin, water-soluble vinyl polymerws, mono and polysaccharides,cellulose derivatives, proteins, watersoluble polyacrylamides, polyvinylpyrrolidone and the like, as well as mixtures of such binding agents.The elements can also contain releasing layers and/or antistatic layers(i.e., crnducting layers).

This invention may be used with emulsions designed for colorphotography; for example, emulsions containing colorforming couplerssuch as those described in Frohlich et al U.S. Pat No. 2,376,679, Jelleyet al. U.S. Pat. No. 2,322,027, Fierke et al. U.S. Pat. No. 2,801,171,Godowsky U.S. Pat. No. 2,698,794, Barr et al. U.S. Pat. No. 3,227,554and Graham et al. U.S. Pat. No. 3,046,129; or emulsions to be developedin solutions containing color-forming couplers such as those describedin Marines et al. U.S. Pat. No. 2,252,718, Carroll et. al. U.S. Pat. No.2,592,243 and Schwann et al. U.S. Pat. No. 2,950,970; and infalse-sensitized color materials such as those described in Hanson U.S.Pat. No. 3,763,549.

A particularly useful multilayer color. emulsion for use in thisinvention is described in Crawford et al. U.S. application Ser. No.447,373 filed Apr. 12, 1965.

Preferakly the reflective layer is permeable to processing solutions forprocessing the exposed radiationsensitive layer or layers. Particularlyuseful reflective layers are permeable to aqueous alkaline solutions,for example, alkaline solutions usedto develop silver halide emulsions.

Reflective layers permeable to processing baths can be composed ofhydrophilic colloids including both naturally occurring substances suchas proteins; for example, gelatin, gelatin derivatives, cellulosederivatives, polysaccarides such as dextran, gum arabic and the like;and synthetic polymeric substances such as water-soluble polyvinylcompounds, for example, polyvinyl alcohol and its derivatives,poly(vinylpyrrolidone), acrylamide polymers and the like, colloidalalbumin, cellulose esters, etc. A useful coverage of colloids is between0.1-2.5 grams/ft. To impart the required reflectivity to the reflectivelayers, light-colored, preferably white, pigments such as titaniumdioxide, zinc oxide, barium sulfate, etc.; are incorporated in thelayer.

An especially preferred pigment is titanium dioxide (rutile form)consisting of particles having an average diameter of 0.1 to 1.0 micronsand prefera bly.0.2 to 0.3 microns. A useful range of pigment is between1.0 910.0 grams/ft.

Alternatively, the reflective layer can be one wherein the reflectivityis the result of voids, as in vesicular material, or reflectivity can beintroduced by means of crystallization or by blushing of vthe layer by anonsolvent.

The composite autostereographic reflection print material is made bycoating the photosensitive layer or layers on the smooth surface of thelenticular support using suitable coating techniques such as thosefamiliar to those skilled in the art. Laminating may also be used. Thereflecting layer is coated over the photosensitive layer or layers usingsuitakle techniques.

The various layers, including the photographic layers, employed in thepractice of this invention can contain light absoring materialsandfilter dyes such as those described in Sawdey U.S. Pat. No.3,253,921;

Gaspar U.S. Pat. No. 2,274,782; Silberstein et al. U.S.

Pat. No. 2,527,583 and Van Campen U.S. Pat. No. 2,956,879. If desired,the dyes can be mordanted; for example, as described in Jones et al.U.S. Pat. No. 3,282,699.

The autostereographic reflection print material that is the subject ofthis invention can be used to make autostereographic reflection prints;e.g., parallax stereograms, parallax panoramagrams, panoramic paradlaxstereograms, etc., by techniques well known to those skilled in the art,such as the techniques descri bed in Kingslake, op' cit. A particularlypreferred method involves the making of a series of negatives in asingle-shot, multiple le'ns camera such as that described in Kingslake,op cit. The resulting negatives were printed on the photographic elementof this invention using, for example, a step-and-repeat printer to forma multiplicity of image elements behind each of the lenticules. Theexposed print is processed by conventional techniques; and the resultingreflection autostereogram can beviewed directly without special viewingaids, giving a panoramic stereoscopic image over an appreciable viewingangle.

The following examples are included for a further understanding of theinvention.

EXAMPLE 1 An autostereographic reflection print element is prepared asfollows:

A subbed cellulose acetate support about 0.010 inch thick whose unsubbedsurface is embossed to form cylindrical lenticules approximately 0.003inch in radius (i.e., about 200 per inch) has coated on its subbedsurface a series of layers in the following order:

1. Gelatin containing a UV absorber 2. A green-sensitive silverchlorobromide gelatin emulsinon containing a magenta dye-forming couplerpl 3. A gelatin interlayer 4. A red-sensitive silver chlorobromidegelatin emulsinon containing a cyan dye-forming coupler 5. A gelatininterlayer 6. A blue-sensitive silver chlorobromide gelatin emulsioncontaining a yellow dye-forming coupler 7. A gelatin interlayer 8. Alayer containing gelatin at a coverage of 0.5

gram/ft and titanium dioxide (rutile form) at a coverage of 3.0 grams/ft9. A gelatin overcoat.

Using the element just described, an autostereographic photographicprint is prepared as follows. A subject is photographed using aconventional color negative film by means of a special eight-lens cameradesigned to make eight simultaneous exposures in focus alignment andstereographic relationship with one another and linearly disposed alongthe fllm. The negative film is processed and the resulting array ofcolor negatives is printed onto the light-sensitive autostereographicprint element hereinbefore described using a printer which exposes theeight separate negative images. The exposures are made such that theimages recorded by the multicolor print emulsions behind the lenticulesbear'the crrrect stereographic relationship to one another. The exposedprint is processed according to a conventional color process, as forexample, that which is given in Example I of U.S. Pat. No. 2,956,879.The presence of the TiO containing reflective layer causes nodifficulties in processing.

WHen the print is viewed by reflected light from the lenticular side, anexcellent stereoscopic effect is observed. Similar results are obtainedwith other reflective layers, including barium sulfate, zinc oxide, andblushed cellulose acetate.

Example 2 Example 3 An autostereographic reflection print element isprepared as in Example 1 except that the multicolor photosensitivelayers are replaced by a black-and-white gelatin photographic silverchlorobromide emulsion layer. The subject is photographed on aconventional black-and-white negative film in the same eight-lens cameradescribed in Example 1,, The exposed negative is processedconventionally and printed as described in Example 1. The print isprocessed conventionally and shows an excellent stereoscopic image whenviewed by reflected light from the lenticular side.

Similar results are obtained with otehr radiationsensitive layersincluding diazo, silver-dye salts, etc.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

We claim:

1. An autostereographic light-sensitive element comprising a transparentsupport having on one surface a multiplicity of lenticules, having onthe opposite surface at least one light-sensitive layer and having a reflective layer coated over said light-sensitive layer farthest from saidsupport, said reflective layer being permeable to aqueous alkalinesolutions.

2. The element of claim 1 in which said light sensitive layer is asilver halide emulsion layer.

3. The element of claim 1 in which said opposite surface has thereon amultilayer color system.

4. The element of claim 1 in which the reflective layer comprises ahydrophilic colloid containing a reflective pigment.

5. The element of claim 4 in which the reflective pigment is titaniumdioxide.

6. The element of claim 5 in which the colloid is gelatin.

7. The element of claim I in which the lenticular frequency is to 300per inch.

8. The element of claim 1 in which the transparent support is acellulose ester.

9. The element of claim 8 in which the cellulose ester is cellulosetriacetate.

10. An element of claim 1 in which said opposite surface has thereon agreen-sensitive silver halide emulsion, a red-sensitive silver halideemulsion, and a bluesensitive silver halide emulsion.

2. The element of claim 1 in which said light sensitive layer is asilver halide emulsion layer.
 3. The element of claim 1 in which saidopposite surface has thereon a multilayer color system.
 4. The elementof claim 1 in which the reflective layer comprises a hydrophilic colloidcontaining a reflective pigment.
 5. The element of claim 4 in which thereflective pigment is titanium dioxide.
 6. The element of claim 5 inwhich the colloid is gelatin.
 7. The element of claim 1 in which thelenticular frequency is 150 to 300 per inch.
 8. The element of claim 1in which the transparent support is a cellulose ester.
 9. The element ofclaim 8 in which the cellulose ester is cellulose triacetate.
 10. Anelement of claim 1 in which said opposite surface has thereon agreen-sensitive silver halide emulsion, a red-sensitive silver halideemulsion, and a blue-sensitive silver halide emulsion.